1. Field of Invention
The present invention relates to a liquid crystal display device and an electronic apparatus, and more particularly, to a liquid crystal display device using vertical alignment type liquid crystals.
2. Description of Related Art
Related liquid display device can include a transflective liquid crystal display device operated in alignment direction, when a voltage is applied, of the liquid crystal molecule reflective and transmissive modes. As such a transflective liquid crystal display device, there has been proposed a transflective liquid crystal display device in which a liquid crystal layer is interposed between upper and lower substrates, a reflecting film made of metal, such as aluminum where light-transmitting window is formed, for example, is provided on an inner surface of the lower substrate, and the reflecting film also serves as a transflective plate. In this case, in the reflective mode, external light enters the upper substrate, passes through the liquid crystal layer, reflects from a reflecting film on the inner surface of the lower substrate, passes through the liquid crystal layer again, and exits from the upper substrate, so that display can be made. In the transmissive mode, light of a backlight enters the lower substrate, passes through the window portion of the reflecting film, passes through the liquid crystal layer, and exits from the upper substrate to the outside, so that display can be made. Therefore, a portion, of the region where the reflecting film is formed, where the window portion is formed, serves as the transmissive display region, and the remaining portion serve as the reflective display region.
In the related transflective liquid crystal display device, there can be a problem in that a viewing angle in the transmissive display is narrow. This problem is involved in the limitation that a transflective plate is provided in the inner surface of the liquid crystal cell in order to prevent parallax, and thus, the reflective display is performed with only one polarizing plate provided on observer's side, so that the degree of freedom in an optical design is lowered. In order to solve the problem, in “Development of transflective LCD for high contrast and wide viewing angle by using homeotropic alignment”, M. Jisaki et al., Asia Display/ID W'01, p. 133-136 (2001), there is proposed a new liquid crystal display device using vertically aligned liquid crystal molecules. The characteristics thereof are as follows:                (1) A VA (vertical alignment) mode is employed. In the VA mode, liquid crystal molecules whose dielectric anisotropy is negative are vertically aligned on a substrate, and when a voltage is applied, the liquid crystal molecules are allowed to tilt.        (2) A multi-gap structure is employed. In the multi-gap structure, the thickness of the liquid crystal layer in the transmissive and reflective regions are made different from each other.        (3) An alignment division structure is employed. In the alignment division structure, the transmissive display region has a shape of regular octagon, and a protrusion is provided at the center of the transmissive display region on the opposite substrate in order to allow the liquid crystal molecules within the transmissive display region to be tilted in all directions.        
On the other hand, in Japanese Unexamined Patent Application Publication No. Heisei 11-242225 there is disclosed a technique for forming a slit in an electrode as alignment controlling means of liquid crystal molecules other than the aforementioned protrusion when the vertically aligned liquid crystal is used.
As described above, the direction that the liquid crystal molecules are tilted in the transmissive display region can be controlled using the protrusion provided at the center of the transmissive display region. However, a device for controlling the direction that the liquid crystal molecules are tilted in the reflective display region is not mentioned. If the direction that liquid crystal molecules are tilted is not controlled and the liquid crystal molecules are tilted disorderly, discontinuous lines, called “disclination”, occur at the boundary between different liquid crystal alignment regions, so that afterimage may be generated. In addition, since the alignment regions of the liquid crystal have different viewing characteristics, there is a problem in that a spotted pattern may be generated as the liquid crystal display device is viewed from an oblique direction.
In addition, in Japanese Unexamined Patent Application Publication No. Heisei 11-242225, the direction that the liquid crystal molecules are tilted is controlled using the protrusion or using a transverse electric field generated by providing the slit to the electrode. However, this approach is provided for only the transmissive liquid crystal display device, but it is not suitably provided for a transflective liquid crystal display device using alignment direction, when a voltage is applied, of the liquid crystal molecule reflective and transmissive modes.